When should you buy? Downtime is a killer with a curb and gutter machine. With other pieces of equipment, you lose the operator’s productivity for that day. But with a curb and gutter machine, downtime means a crew of six to 10 laborers being paid without being productive, losing a load or two of concrete ($1,500 to $2,000) and holding up a general contractor who is waiting to pave asphalt when the curbing is finished. When a machine has so many hours on it that a breakdown becomes a consideration each time you pour, you are overdue for a replacement.